Primary malignant melanoma originating from the small intestine is extremely rare. Only a limited number of cases are described in the literature. Most commonly small intestine is affected by metastatic tumors from other primary lesions. We present a case of a 68-years old male diagnosed with primary malignant melanoma as an ulcerated and bleeding mass in the jejunum - located 40 cm away from the Treitz band. In our case the diagnosis was confirmed at laparotomy and enterectomy.
Histology revealed a neoplastic infiltration involving the entire intestinal mucosa, with atypia of neoplastic cells and immunoreactivity to HMB45(+), Melan A(+) and S100(+), confirming the diagnosis of melanoma. There was not revealed a primary lesion in the skin, eye, anus, rectum or in other location by the post-operative investigation.
An eleven-month close follow-up has not revealed any metastasis.
Therefore a definitive diagnosis of primary malignant melanoma was set.
KEY WORDS: Malignant melanoma - Small intestine - Gastrointestinal melanoma.
